Field of the Invention
The present invention relates to an image recording apparatus that records image data on a recording medium, and transfers the image data recorded on the recording medium to an external apparatus, a control method of the same, and a recording medium.
Description of the Related Art
A digital video camera (hereinafter, simply referred to as a “video camera”) converts an optical image into an electrical signal using an image sensor, and records the electrical signal as digital image data on an internal memory of the camera or a removable recording medium such as a CF card and an SD memory card. The recorded digital image data can be transferred to an external device such as a personal computer (PC) and a mobile terminal (smartphone, tablet terminal, etc.) using various communication units including a universal serial bus (USB) and a wireless local area network (LAN).
In recent years, a function of transferring data via a wireless LAN has been widespread in particular. Such a function realizes data transfer between a video camera that has acquired authentication of the Wireless Fidelity (Wi-Fi), and a PC or a mobile terminal. General data transfer methods include a File Transfer Protocol (FTP), a HyperText Transfer Protocol (HTTP), a Real-time Transport Protocol (RTP), and the like. In transferring digital image data such as movie data obtained through image capturing performed by the video camera, the FTP is often used. The FTP is often used as a file transfer protocol functioning on a higher layer of a Transmission Control Protocol/Internet Protocol (TCP/IP). The video camera operates as an FTP client, and transfers image data to an external device such as a PC and a mobile terminal that has an FTP server function, via an FTP command.
In particular, many of video data handled in Electronic News Gathering (ENG) require immediacy. It is therefore required that digital image data can be promptly transferred via a network.
Japanese Patent Laid-Open No. 2009-225116 discloses a video recording apparatus that transfers, through network transmission, recorded video to an apparatus located at a remote place. The video recording apparatus searches a keyword-weight correspondence dictionary for a keyword that has been input from a keyword input unit during the recording of a movie file, and records a corresponding weight in association with a time on the movie file. When transferring the movie file through a network, the video recording apparatus divides the movie file as a separate movie file for transfer, every certain period of time. The video recording apparatus sequentially transfers the obtained movie files for transfer from movie files having larger total weights associated with the respective times. If the transfer of all the movie files for transfer is ended, a playlist generation unit generates a playlist in which the transferred files are rearranged in the order of record times. The video recording apparatus then transfers the generated playlist.
In addition, Japanese Patent Laid-Open No. 2005-328154 discloses a recording apparatus that records video data obtained by an imaging unit, on a randomly-accessible recording medium. The recording apparatus records video data output from an image sensor, on a first file provided in the recording medium. If a division instruction unit receives, during the image capturing performed by the image sensor, a division instruction input from a user, the recording apparatus records video data that has been output from the image sensor from the time point when the division instruction had been received, on a second file provided in the recording medium.